Water-tube boiler and superheater therefor



R. s PORTHA M AND J. DORNAN. WATER TUBE BOILER AND SUPERHEATER THEREFOR. I

APPLICATION FILED SEPT. I7, 1918.

Patented Apr. 19, 1921.

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WATER-TUBE'BOILER AND SUPERHEATER THEREFOR. 7

Specification of Letters Patent Patented Apr. 19, 1921.

Application filed September 17, 1918. Serial No. 254,445.

T 0 all whom it may concern Be it knownthat we, ROLAND SYDNEY' PORTHA'M and JAMES DORNAN, both subjects of the King of Great Britain and Ireland, and both residing at 22 Billiter street, London, E. C. 3, England, have invented certain new and useful Improvements in and Relating to ater-Tube Boilers and Superheaters Therefor, of which the following is a specification.

This invention relates to water tube boilers wherein superheaters are provided, the elements or pipes of which are of thereturn conduit type, and project between the boiler tubes, each element or section of an element being disposed between adjacent rows of boiler tubes.

In such arrangements, in view of the staggering of the boiler tubes, it is advisable to insert the superheater pipes diagonall into the spaces between the boiler tubes. (aonse quently, in the case 'where the header or headers to which the elements are connected is or are arranged vertically or parallel to the boiler tubes, and the elements project away from the header or headers, it will be seen thatthe header must be set a considerable distance from the position where the elements of the superheater enter the spaces between the boiler tubes, in order to avoid fouling of the header when inserting or withdrawing the elements. tates long pipe ends for the elements and ineflicient utilization of the available heating area.

One object of the present invention is to provide an improved arrangement of superheater in which the objection above referred to is avoided, whereby a compact arrangement of elements and headers is effected, and easy insertion or withdrawal of the individual elements may be accomplished.

it further object of the present invention is to provide an improved arrangement of the elements whereby a more effective distribution of the superheating surface is attained throughout the boiler.

According to one feature of the invention,the surface or surfaces of the header or headers to which the ends of the superheater elements are attached is or are arranged parallel or substantially parallel to the planes containing the axes of the elements.

Preferably a divided header of triangular shape is provided, the base being arranged parallel to the, longitudinal axis of This necessi the boiler the apex of the triangle being remote from the boiler tubes.

According to a further feature of the invention, in order to distribute the elements of the super-heater evenly among the whole of the boiler tubes, the elements in each group are arranged to project alternately in either diagonal direction, whereby a greater percentage of the hot combustion gases is brought into contact with the superheater elements.

Such alternation may be effected by arranging the first element of a group in one direction, the second element projecting in the other direction and so on, or the elements may be arranged in groups of two or more as will be readilyunderstood.

In the accompanying drawings:

Figure 1 shows in elevation a water tube boiler of the Yarrow type having a superheater applied thereto according to the invention;

Fig. 2 is a plan, corresponding to Fig. 1;

Fig. 3 is a plan of a modification.

In carrying the invention into effect as applied, for example, to a water tube boiler of the Yarrow type, as shown in Figs. 1 and 2 and having an upper steam and water drum at and two lower water drums 5 (one only being shown) connected thereto by banks of water tubes 6, the steam collecting and distributing headers 7, or a plurality thereof, are disposed within the casing of the boiler, and on the side of the boiler tubes remote from the furnace, the passages of the header being parallel to the boiler tubes. The header is divided and is of triangular shape, the base 8 of the triangle being arranged as near as practicable to the boiler tubes 6 and parallel thereto.

The header is divided by a wall 9 parallel to the base of the triangle, the base chamber 10 thus formed preferably being used for saturated steam. Instead of a divided header, in some cases two headers may be used.

Superheater elements comprising U-tubes ll of single or multiple form are connected preferably to either slant side 12 of the triangular header and project between the water tubes 6 of the boiler so that each element or section of an element is arranged between adjacent rows of water tubes.

In the case of a multiple U-tube, the various limbs thereof may have one or more rows of Water tubes disposed between them. The

free ends 13 of the superheater elements which project toward the furnace may be supported in any suitable way. For example, each element may be provided with projections which contact with an adjacent element and thus act as distance pieces, the lowest element being supported by a suitable member projecting upward from the boiler drum 5. V

The slant sides 12 of the triangle are arranged parallel or substantially parallel to the planes containing the axes of the superheater tubes 11, and the header or headers 7 is or are arranged in such a position that the elements 11 may be readily inserted or withdrawn without fouling the header. The

elements 11 may be connected to the header in any suitable way, for example, they may be expanded into holes therein, or preferably they may have collars l4 and be fastened to the header by bridge pieces 15 bearing upon said collars.

Although the header has-been referred to as triangular, it need not be confined to this shape, as any other shaped header may be used provided the surface or surfaces to which the elements are attached is parallel or substantially parallel to the plane of the axes'of the elements and so disposed as to allow easy insertion and withdrawal of the elements. 7

In order to admit the insertion of the elements between the boiler tubes, the pitchrof the'latter maybe adjusted.

The combustion gases flowing between the boiler tubes adjacent the header may be intercepted by providing at the ends of the base of the header fins or projecting pieces 16 (as shown in Fig. 3) which may project as near as possible to the boiler tubes.

flor the purpose of utilizing the available heating area to the best possible advantage.

the superheater elements in 'each group of elements may be arranged to project alternately in either diagonal direction as shown in Fig. 3, the two sets 17 and 18 in each case preferably being inserted between the boiler tubes at the same point.

The elements in each group may be arranged so that the odd numbered elements project in one'direction while the evens project in the other direction; or the group of elements may be divided into a number of smaller groups which alternately project in either direction.

The superheater according to the invention may be arranged at any suitable'angle, horizontally, vertically or otherwise, according to the boiler to which the invention is applied.

The invention may be applied to water tube boilers other than the Yarrow type, for example, in the case of a Babcocl: and l/Vilcox boiler, the elements will preferably project vertically among the boiler tubes, the header or headers being arranged above the boiler tubes.

Also it is to be understood that the use of the header having the surface or surfaces to which the elements are connected, arranged parallel to the planes of the axes of the elements, is not to be limited to a superheater in which the elements alternately project in either direction.

When using the crossed arrangement of elements, in some cases the type of header described above may be dispensed with and other types of header utilized.

having now described our invention, what we claim as new and desire to secure by Letters Patent is N A water tube boiler comprising upper drum and lower drums, water tubes connecting said drums, and a superheater comprising divided headers of triangular shape mounted with a base adjacent the water tubes, and elements of multiple U-formation connected to the slant sides of said headers and projecting diagonally into but not beyond the banks of water tubes, each element veing disposed between adjacent diagonal rows of boiler tubes whereby the superheater elements are subjected to the same degree of heat as the adjacent boiler tubes and at the same time, insertion or withdrawal of the superheater elements being effected in a direction parallel to the slant sides of the headers, as set forth. 7 i p In testimony whereof we have signed our names to thisispecification.

ROLAND SYDNEY PORTHAM. JAMES DORNAN. 

